Coal face mine pressure monitoring device and method

Abstract

The invention discloses a coal face mine pressure monitoring device and method, and belongs to the technical field of mine pressure monitoring, and the device comprises a protection box fixed on a main control valve block of a support hydraulic system, a mounting base on the outer wall of a cylinder barrel at the upper end of a stand column and the lower surface of a top beam, and a vibration sensing unit at the central position of the lower surface of the top beam. The two groups of mounting bases are correspondingly arranged up and down, a resonant pressure sensor is embedded in the protection box, and the resonant pressure sensor is in direct butt joint with a pressure measuring opening of the main control valve block through a mining standard high-pressure quick connector. A core pressure monitoring point is transferred to the main control valve block which is relatively stable and can indirectly reflect the load of the stand column from a vulnerable stand column oil cylinder, so that the monitoring point can be prevented from being damaged due to frequent compression and vibration to a certain extent, the maintenance cost is reduced, the service life of equipment is prolonged, and the working efficiency is improved. And reduction of equipment damage and consumption of related materials caused by abnormal mine pressure is facilitated.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of mine pressure monitoring, and particularly relates to a coal mining face mine pressure monitoring device and method. BACKGROUND

[0002] The coal mining face is one of the most important links in coal mine production, and the mine pressure thereof directly affects the safety production and economic benefits of the mine. With the increasing exhaustion of coal resources and the increasing difficulty of coal mining, the mine pressure problem of the coal mining face is increasingly prominent. The traditional mine pressure monitoring means mainly relies on sensors installed on the working face to collect data, but due to the complex and fast-changing environment of the coal mining face, the monitored data is not only easy to be disturbed, but also easy to be damaged due to mechanical impact, with high maintenance cost, and there are problems such as incomplete data collection, low observation accuracy, slow response speed, etc., which cannot meet the real-time monitoring demand under the complex and variable mine pressure condition. SUMMARY

[0003] The purpose of the present application is to provide a coal mining face mine pressure monitoring device and method to solve the problems raised in the background.

[0004] To achieve the above purpose, the present application provides the following technical scheme: a coal mining face mine pressure monitoring device, comprising a protective box fixed on a main control valve block of a support hydraulic system, an installation base on an outer wall of an upper end cylinder of a stand column and a lower surface of a top beam, and a vibration sensing unit at a central position of the lower surface of the top beam, two groups of installation bases are arranged in correspondence with each other, a resonant pressure sensor is embedded in the inside of the protective box, and the resonant pressure sensor is directly connected with a pressure measuring port of the main control valve block through a mine standard high-pressure quick connector; A cover plate is detachably connected to the top of the protective box through bolts, a porous sintered metal damping plug is embedded in the top of the cover plate, the bottom of the porous sintered metal damping plug is in close contact with one end of the resonant pressure sensor, and the porous sintered metal damping plug is used for attenuating high-frequency pressure pulsation.

[0005] Preferably, a protective cover is connected to the bottom of the upper installation base through bolts, the protective cover has a U-shaped structure, a damping sound-absorbing material is embedded in the inner surface of the protective cover, the outer surfaces of the protective cover and the damping sound-absorbing material are both provided with storage holes, a magnetostrictive linear displacement sensor is arranged on the outer surface of the lower installation base, the magnetostrictive linear displacement sensor is located on the inner side of the storage hole, a target is fixed to the bottom of the upper installation base through a non-magnetic stainless steel support, and the measuring head axis of the magnetostrictive linear displacement sensor is always perpendicular to the target plane.

[0006] Preferably, the vibration sensing unit monitors the structure vibration caused by roof activity, coal wall spalling or support action through vibration sensors and intrinsically safe three-axis MEMS accelerometer, which assists in judging the intensity and type of mine pressure activity.

[0007] Preferably, the vibration sensing unit is installed in the area near the hinge point of the shield beam and the top beam.

[0008] Preferably, the bottom of the protective cover is provided with a drain hole, and the outer surfaces of the protective cover and the damping sound-absorbing material are provided with heat dissipation slits, which are located on one side of the storage hole.

[0009] Preferably, the target is made of high magnetic permeability soft iron or corrosion-resistant neodymium iron boron magnet, and the target is cylindrical or sheet-shaped.

[0010] Preferably, the resonant pressure sensor, magnetostrictive linear displacement sensor, vibration sensor and intrinsically safe three-axis MEMS accelerometer are connected to the main control or communication module of the support through short-distance shielded cables, and transmitted to the ground monitoring center through mine ring network or optical fiber.

[0011] Preferably, the mine pressure monitoring method is as follows: S1, first arrange the resonant pressure sensor in the protective box, and directly connect with the pressure measuring port of the main control valve block through the mine standard high-pressure quick connector, to monitor the load of the support hydraulic system; S2, arrange the magnetostrictive linear displacement sensor on the outer surface of the lower mounting base, to monitor the displacement change of the stand column; S3, arrange the vibration sensing unit at the center position of the lower surface of the top beam or in the area near the hinge point of the shield beam and the top beam, monitor the structure vibration caused by roof activity, coal wall spalling or support action through vibration sensors and intrinsically safe three-axis MEMS accelerometer, which assists in judging the intensity and type of mine pressure activity; S4, connect each sensor with the main control or communication module through short-distance shielded cables, to ensure correct cable connection without short circuit or open circuit phenomenon; S5, then calibrate and debug each sensor, to ensure normal operation of the sensor and accurate data acquisition, at the same time, test the data transmission channel to ensure stable data transmission to the ground monitoring center; S6, the ground monitoring center analyzes the received data in real time, uses professional algorithms and models to evaluate the mine pressure activity, and judges the intensity and type of mine pressure activity.

[0012] Preferably, in S6, the content of data analysis includes but is not limited to analyzing the trend of pressure data, identifying pressure mutation points, calculating the rate of change of displacement data, judging the deformation degree of the support, extracting the frequency and amplitude characteristics of the vibration signal, and distinguishing different types of mine pressure activities.

[0013] Preferably, in S6, when mine pressure anomalies or potential safety hazards are found, the ground monitoring center timely sends a warning signal to inform relevant personnel to take corresponding measures.

[0014] Compared with the prior art, the beneficial effects of the present application are: 1、The present application can avoid damage to the monitoring point caused by frequent pressure and vibration to some extent by transferring the core pressure monitoring point from the easily damaged oil cylinder of the stand to the relatively stable main control valve block which can indirectly reflect the load of the stand, thereby reducing maintenance costs, prolonging the service life of the equipment, and helping to reduce equipment damage and related material consumption caused by mine pressure anomalies.

[0015] 2、The present application introduces high-precision relative displacement of the roof beam-stand as the core direct monitoring quantity, captures the most sensitive physical precursor of mine pressure, i.e., the slight compression deformation of the stand, and evaluates the stability of the surrounding rock and the influence of mine pressure on the coal mining face according to the structure and lithology of the surrounding rock, thereby improving the accuracy of mine pressure monitoring.

[0016] 3、The present application integrates a variety of sensors such as a resonant pressure sensor, a magnetostrictive linear displacement sensor, a vibration sensor, and an intrinsically safe three-axis MEMS accelerometer to comprehensively monitor the mine pressure of the coal mining face. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic diagram of the three-dimensional structure of the present application; Figure 2 is a schematic diagram of the layout of the present application; Figure 3 is a schematic diagram of the plane assembly structure of the protective box of the present application; Figure 4Structure schematic diagram of the resonant pressure sensor and the porous sintered metal damping plug of the present application; Figure 5 Schematic diagram of the resonant pressure sensor of the present application; Figure 6 Structure schematic diagram of the assembled protective cover and the damping sound-absorbing material of the present application; Figure 7 Flow chart of the mine pressure monitoring of the present application.

[0018] In the figure: 1, protective box; 2, mounting base; 3, vibration sensing unit; 4, cover plate; 5, porous sintered metal damping plug; 6, resonant pressure sensor; 7, protective cover; 8, damping sound-absorbing material; 9, storage hole; 10, magnetostrictive linear displacement sensor; 11, slit; 12, target; 13, drain hole. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0020] Please refer to Figures 1-7 The present application provides a mine pressure monitoring device for a coal mining face, which comprises a protective box 1 fixed on a main control valve block of a support hydraulic system, a mounting base 2 on an outer wall of a cylinder barrel at an upper end of a stand column and a lower surface of a top beam, and a vibration sensing unit 3 at a central position of the lower surface of the top beam. Two groups of the mounting bases 2 are arranged in correspondence with each other in up and down directions. A resonant pressure sensor 6 is embedded in an inner portion of the protective box 1. The resonant pressure sensor 6 is directly connected with a pressure measuring port of the main control valve block through a mine standard high-pressure quick connector. A cover plate 4 is detachably connected to a top portion of the protective box 1 through bolts. A porous sintered metal damping plug 5 is embedded in a top portion of the cover plate 4. A bottom portion of the porous sintered metal damping plug 5 is in close contact with one end of the resonant pressure sensor 6. The porous sintered metal damping plug 5 is used for attenuating high-frequency pressure pulsation.

[0021] Further, the protection box 1 is made of high-strength mining explosion-proof shell, such as stainless steel or special engineering plastic, with protection level of IP65 or above, which can resist dust, water and mechanical impact on the coal mining face, and protect the internal resonant pressure sensor 6 from the erosion of harsh environment. At the same time, the protection box 1 can also provide a rigid mounting base for the resonant pressure sensor 6, which is fixed by bolts or clamping slots to ensure the stability of the pressure transmission path and avoid pressure monitoring errors caused by loose installation. The cover plate 4 is designed to be detachable by bolts, which provides an operation channel for the maintenance and calibration of the resonant pressure sensor 6 inside the protection box 1. When disassembled, the entire protection box 1 does not need to be removed, reducing the workload of operation and maintenance. After fixing the resonant pressure sensor 6 inside the protection box 1, the top of the protection box 1 is closed to block the intrusion of large rocks and debris, and the sealing rubber ring is used to strengthen the dust and water resistance of the protection box 1. Then, the resonant pressure sensor 6 inside the protection box 1 is directly connected to the pressure measuring port of the main control valve block through a mining standard high-pressure quick connector, which minimizes the connection pipeline. The mining standard high-pressure quick connector is DN4 or DN6 with a self-sealing valve. The connector is directly connected to the valve block pressure measuring port without an intermediate hose, reducing resonance and leakage points. The axis of the resonant pressure sensor 6 is perpendicular to the valve block mounting surface as much as possible. The porous sintered metal damping plug 5 uses the porous structure of metal sintered material to buffer and dissipate the high-frequency pressure pulsation of the hydraulic system, such as the action of the reversing valve and the impact of the oil cylinder, thereby attenuating the amplitude of the pressure fluctuation. At the same time of attenuating the pulsation, it ensures the effective transmission of the steady-state pressure, ensuring that the resonant pressure sensor 6 can monitor both dynamic pressure changes and static pressure references. The resonant pressure sensor 6 is based on the resonance principle, such as tuning fork resonance or silicon resonance, which is within the scope of existing technology, and can accurately measure the pressure value of the support hydraulic system, such as the working resistance of the column and the pressure loss of the control valve group.

[0022] The pressure monitoring process: the pressure of the support hydraulic system, such as the pressure of the column oil cylinder, enters the protection box 1 through the main control valve block pressure measuring port and the mining standard high-pressure quick connector. The pressure first passes through the porous sintered metal damping plug 5, where the high-frequency pulsation is filtered by the pore structure. Then the steady-state pressure and low-frequency fluctuation are transmitted to the resonant pressure sensor 6. The resonant pressure sensor 6 converts the pressure physical quantity into a frequency signal, such as a resonant frequency that changes linearly with pressure, which is transmitted to the acquisition substation or ground system through a cable. The frequency signal is analyzed by monitoring software to display the support working resistance and pressure change trend in real time, which is used to determine whether the initial support force meets the standard and the cycle pressure intensity.

[0023] The bottom of the upper mounting base 2 is connected with a protective cover 7 through bolts, and the protective cover 7 is in a U-shaped structure, the inner surface of the protective cover 7 is embedded with damping sound-absorbing material 8, the outer surfaces of the protective cover 7 and the damping sound-absorbing material 8 are provided with storage holes 9, the outer surface of the lower mounting base 2 is provided with a magnetostrictive linear displacement sensor 10, and the magnetostrictive linear displacement sensor 10 is located on the inner side of the storage hole 9, the bottom of the upper mounting base 2 is fixed with a target 12 through a non-magnetic stainless steel support, the measuring head axis of the magnetostrictive linear displacement sensor 10 is always perpendicular to the plane of the target 12, the target 12 is made of high magnetic permeability soft iron or corrosion-resistant neodymium iron boron magnet, and the target 12 is in a cylindrical or sheet shape, the bottom of the protective cover 7 is provided with a drain hole 13, the outer surfaces of the protective cover 7 and the damping sound-absorbing material 8 are provided with heat dissipation slits 11, and the heat dissipation slits 11 are located on one side of the storage hole 9.

[0024] Further, the mounting base 2 is made of high-strength alloy steel, and is rigidly connected to the outer wall of the column cylinder and the lower surface of the top beam through high-strength bolts or welding, the mounting base 2 has a precisely processed flat surface and a positioning pin hole, providing a precise mounting surface and a fixing hole for the magnetostrictive linear displacement sensor 10 and the target 12; The magnetostrictive linear displacement sensor 10 is rigidly fixed on the mounting base 2 of the outer wall of the upper end cylinder of the column, and is located as close as possible to the connecting pin shaft of the top beam and the column, and is selected from the area of the cylinder which is flat, has no weld seam and is far away from the moving parts, and the target 12 is rigidly fixed on the mounting base 2 of the lower surface of the top beam through a non-magnetic stainless steel support, and is located on the other side of the connecting pin shaft in strict correspondence with the mounting point of the magnetostrictive linear displacement sensor 10, so as to ensure that the target 12 is in a stable state in all designed postures of the support, i.e. the maximum support height, the minimum height and the maximum inclination, the target 12 is made of high magnetic permeability soft iron or corrosion-resistant neodymium iron boron magnet, and provides a magnetic field target for the magnetostrictive linear displacement sensor 10, and the target 12 is in a cylindrical or sheet shape, so as to ensure that the sensor can stably and accurately monitor the displacement, and the measuring head axis of the magnetostrictive linear displacement sensor 10 is always perpendicular to the plane of the target 12, and the measuring distance is within the designed range; The protective cover 7 is a detachable U-shaped steel protective cover 7, which is fixed on the mounting base 2 of the lower surface of the top beam through bolts, and completely covers the magnetostrictive linear displacement sensor 10, the target 12 and the measuring gap. The bottom of the protective cover 7 is provided with a drain hole 13 for draining the accumulated water in the protective cover 7, so as to avoid water soaking the sensor and other components, and to ensure that the device can work normally in a humid coal mining environment, the side surface of the protective cover 7 is provided with heat dissipation slits 11 for dissipating the heat generated by the work of the sensor and other components, so as to maintain the stable working temperature of the components, improve the reliability and service life of the device, and the inner wall of the protective cover 7 can be attached with damping sound-absorbing material 8, which can absorb and attenuate the vibration noise from the outside, such as the sound generated by the action of the support or the impact of coal and rock, so as to reduce the interference with the monitoring of the magnetostrictive linear displacement sensor 10, and improve the accuracy of the displacement data.

[0025] Displacement monitoring process: the lower mounting base 2 fixes the magnetostrictive linear displacement sensor 10, and the upper base fixes the target 12. When the support column extends or the roof beam sinks, the relative distance between the magnetostrictive linear displacement sensor 10 and the target 12 changes, triggering the signal output of the magnetostrictive linear displacement sensor 10. Then, the roof pressing situation is judged by analyzing the displacement data and pressure data, and when the displacement continues to exceed the limit and the pressure drops, the support instability is warned.

[0026] The vibration sensing unit 3 monitors the structural vibration caused by the roof activity, coal wall spalling or support action through the vibration sensor and the intrinsically safe three-axis MEMS accelerometer, which assists in judging the intensity and type of mine pressure activity. The vibration sensing unit 3 is installed near the hinge point of the shield beam and the roof beam.

[0027] Further, the vibration sensing unit 3 is preferentially arranged in the middle area of the lower surface of the roof beam, where the stress is uniform and sensitive to roof activity, or in the area near the hinge point of the shield beam and the roof beam, which is sensitive to torsion and impact. The vibration data can be better collected by flexible deployment according to the actual coal mining situation; The vibration sensor and the intrinsically safe three-axis MEMS accelerometer are used for monitoring. The intrinsically safe three-axis MEMS accelerometer is suitable for the explosion-proof environment of coal mine underground, and can capture vibration information from multiple directions. The structural vibration caused by roof activity such as roof pressing, fracture, coal wall rock falling, support extension or movement, etc. is monitored. Based on the vibration situation, the intensity and type of mine pressure activity are judged, such as large vibration amplitude indicating strong mine pressure activity, and different mine pressure phenomena have different vibration characteristics, which can distinguish whether it is roof pressing or coal wall spalling, etc.

[0028] Vibration monitoring process: when the roof beam is subjected to roof load or coal wall impact, the accelerometer of the vibration sensing unit 3 senses the vibration acceleration, frequency and direction. The vibration sensor and the intrinsically safe three-axis MEMS accelerometer have built-in filtering algorithm, which is used to eliminate the noise of support action, such as high-frequency vibration of push jacking action, and retain the vibration characteristics of mine pressure anomaly, such as low-frequency signal of roof fracture. Combined with vibration data, pressure and displacement data fusion modeling, such as machine learning to identify the pre-pressing signs of pressure slowly rising, displacement slightly changing and low-frequency vibration enhancing as a cycle, the warning accuracy is improved.

[0029] The resonant pressure sensor 6, the magnetostrictive linear displacement sensor 10, the vibration sensor and the intrinsically safe three-axis MEMS accelerometer are connected to the main control or communication module of the support through short-distance shielded cable, and are uploaded to the ground monitoring center through mine ring network or optical fiber.

[0030] Further, the vibration sensor and the intrinsically safe three-axis MEMS accelerometer, the former captures vibration signals, and the latter accurately detects acceleration from multiple dimensions, together monitoring the vibration and movement state of the roof, coal wall and support, assisting in judging the mine pressure activity, and the short-distance shielded cable can ensure that the electrical signals transmitted by the sensor are stable and accurate, so that these sensors can reliably transmit the collected pressure, displacement, vibration and other data to the main control or communication module of the support; Each hydraulic support is an intelligent monitoring node, and the main control or communication modules between the nodes are interconnected through a wireless Mesh network. The main control or communication module of the support: responsible for receiving data from various sensors, playing a role in aggregation and preliminary processing, and preparing for subsequent uploading to the ground; Mine ring network or optical fiber: a network transmission facility dedicated for underground coal mines, the ring network has high reliability, the optical fiber has high transmission speed and strong anti-interference, and they serve as a channel for data transmission from the underground support to the ground, and can stably and efficiently upload the data processed by the main control or communication module of the support to the ground monitoring center; The ground monitoring center: the final receiving and processing end of data, the staff analyzes and monitors the transmitted pressure, displacement, vibration and other data, and once mine pressure anomalies such as pressure mutation, displacement overrun or vibration anomaly are found, timely warning and measures can be taken to ensure the safety of the coal mining face, and through multi-parameter collaborative analysis, a pressure-displacement-vibration correlation model is constructed to realize the leap from single pressure monitoring to mine pressure system behavior identification.

[0031] The working principle and use process of the application: according to the structure size and installation interface of the protection box 1, clean the surrounding impurities of the main control valve block pressure measuring port, ensure that the installation surface is clean and free of oil stains and rust, then accurately embed the resonant pressure sensor 6 into the protection box 1, select a mine standard high-pressure quick connector, check the integrity of the connector sealing ring, apply special sealing grease, then quickly connect the connector with the main control valve block pressure measuring port, after insertion, perform pressure testing to ensure no leakage, and thus accurately monitor the load of the support hydraulic system, providing basic data for subsequent analysis of the support stress state; Then the outer surface of the lower mounting base 2 is polished, degreased and rust-proof treated to improve the installation fit of the magnetostrictive linear displacement sensor 10, then the magnetostrictive linear displacement sensor 10 is fixed on the lower mounting base 2, ensuring that the measuring rod axis of the magnetostrictive linear displacement sensor 10 is strictly parallel to the displacement direction of the stand, and the parallelism error is ≤0.2°, and the displacement is calibrated by selecting at least 5 calibration points in the full range of the sensor using a standard displacement calibration device such as a high-precision displacement table, and the calibration error is ≤0.1mm, realizing accurate monitoring of the displacement change of the stand, and being used for analyzing the stretching and deformation law of the support; If the vibration sensing unit 3 is selected to be installed at the center position of the lower surface of the top beam, the center coordinates need to be determined by means of a laser range finder, and if it is installed in the area close to the hinge point of the top beam, the hinge point position is measured to ensure that the sensor is installed within ±100mm around the hinge point, thereby ensuring effective collection of the vibration of the top plate movement, coal wall spalling and support action; A short-distance shielding cable with anti-electromagnetic interference, waterproof and wear-resistant properties is selected, the cable is cut according to the actual distance between the sensor and the main control or communication module, and the two ends of the cable are well insulated and jointed. When laying, the cable is fixed along the pre-set cable groove of the support or by using a cable clamp to avoid contact with sharp parts of the support and prevent cable damage. Then the two ends of the cable are reliably connected to the terminal of the sensor, main control or communication module. The continuity of the cable is detected by using a multimeter to ensure that there is no short circuit or open circuit. The connection and protection of the cable are checked every certain period of time in the wet underground environment, and the aged and damaged parts are replaced in time to ensure stable signal transmission. After the lines and monitoring devices are installed and laid, the sensors are calibrated and the signal integrity is tested. Then the data from each sensor can be received by the main control or communication module of the support and uploaded to the ground control center. The collected data is analyzed and processed by the ground control center. The time series analysis algorithm such as ARIMA model is used to model the change trend of the pressure data, the pressure mutation recognition threshold is set to automatically identify the pressure mutation point, the correlation between pressure change and mine pressure appearance is analyzed by combining the support working cycle such as initial support, resistance increase and constant resistance stage, the abnormal load condition of the support hydraulic system is judged, then the differential algorithm is used to calculate the change rate of displacement data, the displacement change rate threshold is set, the support deformation degree is judged by combining the cumulative displacement value, when the displacement change rate exceeds the threshold and the cumulative displacement reaches 80% of the allowable deformation of the support, the potential instability risk of the support is warned, the frequency and amplitude characteristics of the vibration signal are extracted by using fast Fourier transform, the vibration characteristic library of different mine pressure activities such as roof pressure, coal wall spalling and normal support action is established, and the mine pressure activity type is distinguished by comparing the real-time vibration characteristics with the characteristic library data by using the pattern recognition algorithm. According to the data analysis result, set yellow warning: abnormal trend of mine pressure activity, such as slow pressure rise, displacement rate slightly exceeds threshold, orange warning: relatively intense mine pressure activity, such as pressure mutation, displacement continues to increase, red warning: mine pressure disaster is about to occur or has occurred, such as vibration amplitude increases sharply, after the ground monitoring center issues a warning, automatically link the underground broadcasting system of coal mine, working face support control system, the broadcasting system broadcasts warning information and evacuation route to the on-site personnel, the support control system automatically adjusts the support liquid supply pressure and support posture according to the warning type, and pushes the warning data to the coal mine safety management platform, so as to facilitate remote command and dispatch of management personnel and take corresponding measures to avoid mine pressure disaster risk.

[0032] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A coal face mine pressure monitoring device, comprising a protective box (1) fixed on the main control valve block of the hydraulic system of the support, an installation base (2) on the outer wall of the upper end cylinder of the column and the lower surface of the top beam, and a vibration sensing unit (3) at the center position of the lower surface of the top beam, two groups of installation bases (2) are arranged in correspondence with each other up and down, characterized in that, The resonant pressure sensor (6) is arranged in the protective box (1) in a built-in mode, and is directly connected with the pressure measuring port of the main control valve block through a mine standard high-pressure quick connector. The top of the protective box (1) is detachably connected with a cover plate (4) through bolts, the top of the cover plate (4) is arranged in a built-in mode with a porous sintered metal damping plug (5), and the bottom of the porous sintered metal damping plug (5) is attached to one end of the resonant pressure sensor (6), and the porous sintered metal damping plug (5) is used for attenuating high-frequency pressure pulsation.

2. The mine pressure monitoring device for a coal mining face according to claim 1, characterized in that, The bottom of the mounting base (2) is connected with a protective cover (7) through bolts, the protective cover (7) has a U-shaped structure, the inner surface of the protective cover (7) is embedded with a damping sound-absorbing material (8), the outer surfaces of the protective cover (7) and the damping sound-absorbing material (8) are provided with storage holes (9), the outer surface of the lower mounting base (2) is provided with a magnetostrictive linear displacement sensor (10), and the magnetostrictive linear displacement sensor (10) is located on the inner side of the storage hole (9), the bottom of the upper mounting base (2) is fixed with a target (12) through a non-magnetic stainless steel support, and the measuring head axis of the magnetostrictive linear displacement sensor (10) is always perpendicular to the plane of the target (12).

3. The mine pressure monitoring device for a coal mining face according to claim 1, characterized in that, The vibration sensing unit (3) monitors the structure vibration caused by the roof activity, coal wall spalling or support action through the vibration sensor and the intrinsically safe three-axis MEMS accelerometer, and assists in judging the intensity and type of mine pressure activity.

4. The mine pressure monitoring device for a coal mining face according to claim 1, characterized in that, The vibration sensing unit (3) is installed in the area close to the hinge point of the top beam of the shield beam.

5. The mine pressure monitoring device for a coal mining face according to claim 2, characterized in that, The bottom of the protective cover (7) is provided with a water drain hole (13), the outer surfaces of the protective cover (7) and the damping sound-absorbing material (8) are provided with heat dissipation slits (11) penetrating through, and the heat dissipation slits (11) are located on one side of the storage hole (9).

6. The mine pressure monitoring device of claim 2, wherein, The target (12) is made of high magnetic permeability soft iron or corrosion-resistant neodymium iron boron magnet, and the target (12) has a cylindrical or sheet shape.

7. The mine pressure monitoring device of claim 3, wherein, The resonant pressure sensor (6), the magnetostrictive linear displacement sensor (10), the vibration sensor and the intrinsically safe three-axis MEMS accelerometer are connected to the main control or communication module of the support through short-distance shielded cables, and are transmitted to the ground monitoring center through mine ring network or optical fiber.

8. A method of monitoring rock pressure at a coal face, suitable for use with a device for monitoring rock pressure at a coal face as claimed in any one of claims 1 to 7, characterised by, The mine pressure monitoring method is as follows: S1, first, the resonant pressure sensor (6) is arranged in the protective box (1), and is directly connected with the pressure measuring port of the main control valve block through the mine standard high-pressure quick connector, so as to monitor the load of the support hydraulic system; S2, the magnetostrictive linear displacement sensor (10) is arranged on the outer surface of the lower mounting base (2), and is used for monitoring the displacement change of the stand column; S3, the vibration sensing unit (3) is arranged at the center position of the lower surface of the top beam or in the area close to the hinge point of the top beam of the shield beam, and the structure vibration caused by the roof activity, coal wall spalling or support action is monitored through the vibration sensor and the intrinsically safe three-axis MEMS accelerometer, so as to assist in judging the intensity and type of mine pressure activity; S4, the sensors are connected with the main control or communication module through short-distance shielded cables, so as to ensure that the cable connection is correct, and there is no short circuit or open circuit phenomenon. S5, then the sensor calibration and debugging, to ensure that the sensor works properly, accurate data acquisition, at the same time, test data transmission channel, to ensure that the data can be stable transmission to the ground monitoring center; S6, the ground monitoring center real-time analysis of the data received, using professional algorithms and models to evaluate the mine pressure activity, to determine the intensity and type of mine pressure activity.

9. A mine pressure monitoring method for a coal face according to claim 8 wherein, In S6, the content of data analysis includes but is not limited to analyzing the trend of pressure data, identifying the pressure mutation point, calculating the change rate of displacement data, judging the deformation degree of support, extracting the frequency and amplitude characteristics of vibration signal, and distinguishing different types of mine pressure activity.

10. The mine pressure monitoring method of a coal mining face according to claim 8, characterized in that, In S6, it also includes that when finding mine pressure anomaly or potential safety hazard, the ground monitoring center sends out early warning signal in time, and informs the relevant personnel to take corresponding measures.

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